Start from her tolerance, not your schedule
Brushing a long-haired cat who hates being groomed is a training project first and a grooming session second. She is not being difficult; past sessions probably hurt, because long hair that has begun to tangle pulls at the skin with every stroke, so she has learned that the brush predicts pain. One long weekly attempt confirms that lesson. Short sessions that end while she is still coping rewrite it. Aim at first for a few calm strokes, not a finished cat, and measure success by how relaxed she was when you stopped.
Rebuild the association in small steps
Choose a moment when she is already drowsy, often after eating, and a place she chose herself rather than a table she is carried to. Begin with stroking using your hand, then a soft grooming glove, for just a few seconds, followed immediately by a small piece of food she genuinely loves. Repeat across several days without increasing the demand. When the glove no longer earns a flinch or a turned head, introduce a wide-toothed comb on the least sensitive area, usually the back, for two or three slow strokes. Grow the area and the time gradually, always finishing before she needs to leave, because ending on your terms while she is calm is what builds the next session.
Work the coat in the order mats form
Long hair tangles first where it is finest and where it rubs: behind the ears, in the armpits, along the belly, and in the trousers between the hind legs. Once she accepts combing, visit those friction zones briefly and often rather than saving them for a marathon. Lift the hair in layers and comb from the ends toward the skin in short passes, holding the base of any tangle with your fingers so the skin is not tugged. A slicker brush can finish the topcoat on the back, but it skims over forming mats underneath, so the comb reaching the skin is the tool that matters for this cat.
Handling a mat that is already there
Do not brush through a tight mat or pull a comb against one; that is the exact pain that taught her to hate this. Small, loose tangles can be teased apart with fingers and a comb worked from the outer edges. A mat that sits flat against the skin, or one over the armpits or groin, should be clipped out by a groomer or veterinary team, because skin under a mat is thin, irritated, and easy to nick with home scissors. Clearing the painful coat professionally and then maintaining the fresh coat with your short sessions gives her a clean start instead of another bad memory.
When resistance is telling you something else
Contact your vet if a cat who once tolerated grooming suddenly objects, if she guards one particular spot, or if you find lumps, scabs, or sore skin under the hair as you work. Pain from joints, teeth, or skin can all present as a cat who will not be brushed. Also seek help if her coat mats again within days despite regular combing, since excessive greasiness or a change in coat texture can have a medical cause worth checking.
Keeping every helper on the same gentle plan
This method fails if one person is patient for a week and another pins her down for a full brush on the weekend. The steps and the stopping rule have to be shared, not improvised. You can write the session order and her current comfort level into KinsLe Care Teams so anyone who brushes her follows the same gradual approach.